// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_DNS_MOJO_HOST_RESOLVER_IMPL_H_
#define NET_DNS_MOJO_HOST_RESOLVER_IMPL_H_

#include <set>

#include "base/macros.h"
#include "base/threading/thread_checker.h"
#include "net/interfaces/host_resolver_service.mojom.h"
#include "net/log/net_log.h"

namespace net {

class HostResolver;

// MojoHostResolverImpl handles mojo host resolution requests. Inbound Mojo
// requests are sent to the HostResolver passed into the constructor. When
// destroyed, any outstanding resolver requests are cancelled. If a request's
// HostResolverRequestClient is shut down, the associated resolver request is
// cancelled.
class MojoHostResolverImpl {
public:
    // |resolver| is expected to outlive |this|.
    MojoHostResolverImpl(net::HostResolver* resolver, const BoundNetLog& net_log);
    ~MojoHostResolverImpl();

    void Resolve(interfaces::HostResolverRequestInfoPtr request_info,
        interfaces::HostResolverRequestClientPtr client);

    bool request_in_progress() { return !pending_jobs_.empty(); }

private:
    class Job;

    // Removes |job| from the set of pending jobs, and deletes it.
    void DeleteJob(Job* job);

    // Resolver for resolving incoming requests. Not owned.
    net::HostResolver* resolver_;

    // The BoundNetLog to be passed to |resolver_| for all requests.
    const BoundNetLog net_log_;

    // All pending jobs, so they can be cancelled when this service is destroyed.
    // Owns all jobs.
    std::set<Job*> pending_jobs_;

    base::ThreadChecker thread_checker_;

    DISALLOW_COPY_AND_ASSIGN(MojoHostResolverImpl);
};

} // namespace net

#endif // NET_DNS_MOJO_HOST_RESOLVER_IMPL_H_
